Compound heterozygosity for hemoglobin C and hemoglobin Korle-Bu

Area of Science:

• Hematology
• Genetics
• Molecular Biology

Background:

• Hemoglobinopathies are a group of inherited blood disorders.
• Compound heterozygosity involves having two different mutations in the same gene.
• Hemoglobin C and Hemoglobin Korle-Bu are known variants affecting red blood cell function.

Observation:

• A case of compound heterozygosity for hemoglobin C (beta6 Glu-->Lys) and hemoglobin Korle-Bu (beta73 Asp-->Asn) is presented.
• This is the third reported case of this specific genotype.
• Integrated diagnostic data included cation exchange high-performance liquid chromatography, hemoglobin electrophoresis, and beta-globin gene sequencing.

Findings:

• The principal hematological finding was microcytosis (small red blood cells) without significant anemia.
• Previous reports of this genotype also noted microcytosis, with variable degrees of hemolytic anemia.
• This specific compound-heterozygous genotype combines two distinct beta-globin gene mutations.

Implications:

• The findings highlight the importance of advanced molecular diagnostics in characterizing complex hemoglobinopathies.
• Anticipating this genotype in individuals of African ancestry is crucial due to the gene frequencies of hemoglobin C and Korle-Bu.
• Understanding this rare genotype contributes to the broader knowledge of hemoglobin variation and its clinical manifestations.